Organic optoelectronic diode and display device

ABSTRACT

Disclosed are an organic optoelectronic device includes an anode and a cathode facing each other and an organic layer disposed between the anode and the cathode, wherein the organic layer includes at least one of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, and the light emitting layer includes a first host, a second host, and a phosphorescent dopant represented by Chemical Formula 4, and a display device including the same.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national phase application based on PCT/KR2018/007516,filed Jul. 3, 2018, which is based on Korean Patent Application No.10-2017-0093029 filed on Jul. 21, 2017, the entire contents of each ofwhich are hereby incorporated by reference.

FIELD OF THE INVENTION

An organic optoelectronic device and a display device are disclosed.

DESCRIPTION OF THE RELATED ART

An organic optoelectronic device (organic optoelectronic diode) is adevice that converts electrical energy into photoenergy, and vice versa.

An organic optoelectronic device may be classified as follows inaccordance with its driving principles. One is a photoelectric devicewhere excitons are generated by photoenergy, separated into electronsand holes, and are transferred to different electrodes to generateelectrical energy, and the other is a light emitting device where avoltage or a current is supplied to an electrode to generate photoenergyfrom electrical energy.

Examples of the organic optoelectronic diode may be an organicphotoelectric device, an organic light emitting diode, an organic solarcell, and an organic photo conductor drum.

Of these, an organic light emitting diode (OLED) has recently drawnattention due to an increase in demand for flat panel displays. Theorganic light emitting diode is a device converting electrical energyinto light by applying current to an organic light emitting material,and has a structure in which an organic layer is disposed between ananode and a cathode. Herein, the organic layer may include a lightemitting layer and optionally an auxiliary layer, and the auxiliarylayer may be, for example at least one layer selected from a holeinjection layer, a hole transport layer, an electron blocking layer, anelectron transport layer, an electron injection layer, and a holeblocking layer.

Performance of an organic light emitting diode may be affected bycharacteristics of the organic layer, and among them, may be mainlyaffected by characteristics of an organic material of the organic layer.

Particularly, development for an organic material being capable ofincreasing hole and electron mobility and simultaneously increasingelectrochemical stability is needed so that the organic light emittingdiode may be applied to a large-size flat panel display.

DESCRIPTION OF THE INVENTION Technical Problem

An embodiment provides an organic optoelectronic device having highefficiency and long life-span.

Another embodiment provides a display device including the organicoptoelectronic device.

Technical Solution

According to an embodiment, an organic optoelectronic device includes ananode and a cathode facing each other and an organic layer disposedbetween the anode and the cathode, wherein the organic layer includes atleast one of a hole injection layer, a hole transport layer, a lightemitting layer, and an electron transport layer, and the light emittinglayer includes a first host represented by Chemical Formula 1, a secondhost represented by a combination of Chemical Formula 2 and ChemicalFormula 3, and a phosphorescent dopant represented by Chemical Formula4.

In Chemical Formula 1,

X¹ is O or S,

Z¹ to Z³ are independently N or CR^(a),

at least two of Z¹ to Z³ are N,

L¹ and L² are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group,

A is a substituted or unsubstituted carbazolyl group,

R¹ is a substituted or unsubstituted C6 to C20 aryl group, a substitutedor unsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, and

R^(a) and R² to R⁴ are independently hydrogen, deuterium, a cyano group,a substituted or unsubstituted C1 to C10 alkyl group, or a substitutedor unsubstituted C6 to C20 aryl group;

wherein, in Chemical Formula 2 and Chemical Formula 3,

Y¹ and Y² are independently a substituted or unsubstituted C6 to C20aryl group, or a substituted or unsubstituted C2 to C30 heterocyclicgroup,

adjacent two *'s of Chemical Formula 2 are linked with Chemical Formula3,

* of Chemical Formula 2 that are not linked with Chemical Formula 3 areindependently C-L^(a)-R^(b),

L^(a), L³, and L⁴ are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group,

R^(b) and R⁵ to R⁸ are independently hydrogen, deuterium, a cyano group,a substituted or unsubstituted C1 to C10 alkyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group;

wherein in Chemical Formula 4,

Z⁴ to Z¹¹ are independently N, C or CR^(c),

the ring C is bound to the ring B through a C—C bond,

iridium is bound to the ring B through a Ir—C bond,

X² is O or S,

R^(c) and R¹⁴ to R¹⁹ are independently hydrogen, deuterium, a halogen,germanium group, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted C1 to C10 alkyl group, asubstituted or unsubstituted C3 to C20 cycloalkyl group, a substitutedor unsubstituted C1 to C10 alkylsilyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group, and

n is an integer ranging from 1 to 3.

According to another embodiment, a display device including the organicoptoelectronic device is provided.

Advantageous Effect

An organic optoelectronic device having high efficiency and a longlife-span may be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are cross-sectional views showing organic light emittingdiodes according to embodiments.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention are described indetail. However, these embodiments are exemplary, the present inventionis not limited thereto and the present invention is defined by the scopeof claims.

In the present specification when a definition is not otherwiseprovided, “substituted” refers to replacement of at least one hydrogenof a substituent or a compound by deuterium, a halogen, a hydroxylgroup, an amino group, a substituted or unsubstituted C1 to C30 aminegroup, a nitro group, a substituted or unsubstituted C1 to C40 silylgroup, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6 toC30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroarylgroup, a C1 to C20 alkoxy group, a C1 to C10 trifluoroalkyl group, acyano group, or a combination thereof.

In one example of the present invention, “substituted” refers toreplacement of at least one hydrogen of a substituent or a compound bydeuterium, a C1 to C10 alkyl group, a C6 to C20 aryl group, or a C2 toC20 heterocyclic group. In addition, in specific examples of the presentinvention, “substituted” refers to replacement of at least one hydrogenof a substituent or a compound by deuterium, a C1 to C4 alkyl group, aC6 to C12 aryl group, or a C2 to C12 heterocyclic group. Morespecifically, “substituted” refers to replacement of at least onehydrogen of a substituent or a compound by deuterium, a C1 to C5 alkylgroup, a phenyl group, a biphenyl group, a terphenyl group, a naphthylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, or a carbazolyl group. In addition, inmost specific examples of the present invention, “substituted” refers toreplacement of at least one hydrogen of a substituent or a compound bydeuterium, a methyl group, an ethyl group, a propanyl group, a butylgroup, a phenyl group, a para-biphenyl group, a meta-biphenyl group, adibenzofuranyl group, a dibenzothiophenyl group, or a carbazolyl group.

In the present specification, when a definition is not otherwiseprovided, “hetero” refers to one including one to three heteroatomsselected from N, O, S, P, and Si, and remaining carbons in onefunctional group.

In the present specification, when a definition is not otherwiseprovided, “alkyl group” refers to an aliphatic hydrocarbon group. Thealkyl group may be “a saturated alkyl group” without any double bond ortriple bond.

The alkyl group may be a C1 to C30 alkyl group. More specifically, thealkyl group may be a C1 to C20 alkyl group or a C1 to C10 alkyl group.For example, a C1 to C4 alkyl group may have one to four carbon atoms inthe alkyl chain, and may be selected from methyl, ethyl, propyl,iso-propyl, n-butyl, iso-butyl, sec-butyl, and t-butyl.

Specific examples of the alkyl group may be a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, a t-butyl group, a pentyl group, a hexyl group, a cyclopropylgroup, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, andthe like.

In the present specification, “an aryl group” refers to a groupincluding at least one hydrocarbon aromatic moiety, and

all elements of the hydrocarbon aromatic moiety have p-orbitals whichform conjugation, for example a phenyl group, a naphthyl group, and thelike,

two or more hydrocarbon aromatic moieties may be linked by a sigma bondand may be, for example a biphenyl group, a terphenyl group, aquarterphenyl group, and the like, and

two or more hydrocarbon aromatic moieties are fused directly orindirectly to provide a non-aromatic fused ring. For example, it may bea fluorenyl group.

The aryl group may include a monocyclic, polycyclic, or fused ringpolycyclic (i.e., rings sharing adjacent pairs of carbon atoms)functional group.

In the present specification, “a heterocyclic group” is a genericconcept of a heteroaryl group, and may include at least one heteroatomselected from N, O, S, P, and Si instead of carbon (C) in a cycliccompound such as an aryl group, a cycloalkyl group, a fused ringthereof, or a combination thereof. When the heterocyclic group is afused ring, the entire ring or each ring of the heterocyclic group mayinclude one or more heteroatoms.

For example, “heteroaryl group” may refer to an aryl group including atleast one heteroatom selected from N, O, S, P, and Si. Two or moreheteroaryl groups are linked by a sigma bond directly, or when theheteroaryl group includes two or more rings, the two or more rings maybe fused. When the heteroaryl group is a fused ring, each ring mayinclude one to three heteroatoms.

Specific examples of the heterocyclic group may include a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, and thelike.

More specifically, the substituted or unsubstituted C6 to C30 aryl groupand/or the substituted or unsubstituted C2 to C30 heterocyclic group maybe a substituted or unsubstituted phenyl group, a substituted orunsubstituted naphthyl group, a substituted or unsubstituted anthracenylgroup, a substituted or unsubstituted phenanthrenyl group, a substitutedor unsubstituted naphthacenyl group, a substituted or unsubstitutedpyrenyl group, a substituted or unsubstituted biphenyl group, asubstituted or unsubstituted p-terphenyl group, a substituted orunsubstituted m-terphenyl group, a substituted or unsubstitutedo-terphenyl group, a substituted or unsubstituted chrysenyl group, asubstituted or unsubstituted triphenylene group, a substituted orunsubstituted perylenyl group, a substituted or unsubstituted fluorenylgroup, a substituted or unsubstituted indenyl group, a substituted orunsubstituted furanyl group, a substituted or unsubstituted thiophenylgroup, a substituted or unsubstituted pyrrolyl group, a substituted orunsubstituted pyrazolyl group, a substituted or unsubstituted imidazolylgroup, a substituted or unsubstituted triazolyl group, a substituted orunsubstituted oxazolyl group, a substituted or unsubstituted thiazolylgroup, a substituted or unsubstituted oxadiazolyl group, a substitutedor unsubstituted thiadiazolyl group, a substituted or unsubstitutedpyridyl group, a substituted or unsubstituted pyrimidinyl group, asubstituted or unsubstituted pyrazinyl group, a substituted orunsubstituted triazinyl group, a substituted or unsubstitutedbenzofuranyl group, a substituted or unsubstituted benzothiophenylgroup, a substituted or unsubstituted benzimidazolyl group, asubstituted or unsubstituted indolyl group, a substituted orunsubstituted quinolinyl group, a substituted or unsubstitutedisoquinolinyl group, a substituted or unsubstituted quinazolinyl group,a substituted or unsubstituted quinoxalinyl group, a substituted orunsubstituted naphthyridinyl group, a substituted or unsubstitutedbenzoxazinyl group, a substituted or unsubstituted benzthiazinyl group,a substituted or unsubstituted acridinyl group, a substituted orunsubstituted phenazinyl group, a substituted or unsubstitutedphenothiazinyl group, a substituted or unsubstituted phenoxazinyl group,a substituted or unsubstituted carbazolyl group, a substituted orunsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, or combination thereof, but are not limitedthereto.

In the present specification, hole characteristics refer to an abilityto donate an electron to form a hole when an electric field is appliedand that a hole formed in the anode may be easily injected into thelight emitting layer, a hole formed in the light emitting layer may beeasily transported into the anode, and a hole may be easily transportedin the light emitting layer due to conductive characteristics accordingto a highest occupied molecular orbital (HOMO) level.

In addition, electron characteristics refer to an ability to accept anelectron when an electric field is applied and that an electron formedin the cathode may be easily injected into the light emitting layer, anelectron formed in the light emitting layer may be easily transportedinto the cathode, and an electron may be easily transported in the lightemitting layer due to conductive characteristics according to a lowestunoccupied molecular orbital (LUMO) level.

Hereinafter, an organic optoelectronic device according to an embodimentis described.

The organic optoelectronic device may be any device to convertelectrical energy into photoenergy and vice versa without particularlimitation, and may be for example an organic photoelectric device, anorganic light emitting diode, an organic solar cell, and an organicphoto conductor drum, and the like.

Herein, an organic light emitting diode as one example of an organicoptoelectronic device is described referring to drawings.

FIGS. 1 and 2 are cross-sectional view showing organic light emittingdiodes according to embodiments.

Referring to FIG. 1 , an organic light emitting diode 100 according toan embodiment includes an anode 120 and a cathode 110 facing each otherand an organic layer 105 interposed between the anode 120 and cathode110.

The anode 120 may be made of a conductor having a large work function tohelp hole injection, and may be for example metal, metal oxide and/or aconductive polymer. The anode 120 may be, for example a metal such asnickel, platinum, vanadium, chromium, copper, zinc, gold and the like oran alloy thereof; metal oxide such as zinc oxide, indium oxide, indiumtin oxide (ITO), indium zinc oxide (IZO), and the like; a combination ofa metal and an oxide such as ZnO and Al or SnO₂ and Sb; a conductivepolymer such as poly(3-methylthiophene),poly(3,4-(ethylene-1,2-dioxy)thiophene) (PEDOT), polypyrrole, andpolyaniline, but is not limited thereto.

The cathode 110 may be made of a conductor having a small work functionto help electron injection, and may be for example metal, metal oxideand/or a conductive polymer. The cathode 110 may be for example a metalsuch as magnesium, calcium, sodium, potassium, titanium, indium,yttrium, lithium, gadolinium, aluminum silver, tin, lead, cesium,barium, and the like or an alloy thereof; a multi-layer structurematerial such as LiF/Al, LiO₂/Al, LiF/Ca, LiF/Al and BaF₂/Ca, but is notlimited thereto.

The organic layer 105 includes a light emitting layer 130.

FIG. 2 is a cross-sectional view showing an organic light emitting diodeaccording to another embodiment.

Referring to FIG. 2 , an organic light emitting diode 200 furtherincludes a hole auxiliary layer 140 in addition to the light emittinglayer 130. The hole auxiliary layer 140 may further increase holeinjection and/or hole mobility and block electrons between the anode 120and the light emitting layer 130. The hole auxiliary layer 140 may be,for example a hole transport layer, a hole injection layer, and/or anelectron blocking layer and may include at least one layer.

The organic layer 105 of FIG. 1 or 2 may further include an electroninjection layer, an electron transport layer, an electron transportauxiliary layer, a hole transport layer, a hole transport auxiliarylayer, a hole injection layer, or a combination thereof even if they arenot shown.

The organic light emitting diodes 100 and 200 may be manufactured byforming an anode or a cathode on a substrate, forming an organic layerusing a dry film formation method such as a vacuum deposition method(evaporation), sputtering, plasma plating, and ion plating or a wetcoating method such as spin coating, dipping, and flow coating, andforming a cathode or an anode thereon.

An organic optoelectronic device according to an embodiment includes ananode and a cathode facing each other, and an organic layer disposedbetween the anode and the cathode, wherein the organic layer includes atleast one of a hole injection layer, a hole transport layer, a lightemitting layer, and an electron transport layer and the light emittinglayer includes a first host represented by Chemical Formula 1, a secondhost represented by a combination of Chemical Formula 2 and ChemicalFormula 3, and a phosphorescent dopant represented by Chemical Formula4.

In Chemical Formula 1,

X¹ is O or S,

Z¹ to Z³ are independently N or CR^(a),

at least two of Z¹ to Z³ are N,

L¹ and L² are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group,

A is a substituted or unsubstituted carbazolyl group,

R¹ is a substituted or unsubstituted C6 to C20 aryl group, a substitutedor unsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, and

R^(a) and R² to R⁴ are independently hydrogen, deuterium, a cyano group,a substituted or unsubstituted C1 to C10 alkyl group, or a substitutedor unsubstituted C6 to C20 aryl group;

wherein, in Chemical Formula 2 and Chemical Formula 3,

Y¹ and Y² are independently a substituted or unsubstituted C6 to C20aryl group, or a substituted or unsubstituted C2 to C30 heterocyclicgroup,

adjacent two *'s of Chemical Formula 2 are linked with Chemical Formula3,

* of Chemical Formula 2 that are not linked with Chemical Formula 3 areindependently C-L^(a)-R^(b),

L^(a), L³, and L⁴ are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group, and

R^(b) and R⁵ to R⁸ are independently hydrogen, deuterium, a cyano group,a substituted or unsubstituted C1 to C10 alkyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group;

wherein, in Chemical Formula 4,

Z⁴ to Z¹¹ are independently N, C or CR^(c),

the ring C is bound to the ring B through a C—C bond,

iridium is bound to the ring B through a Ir—C bond,

X² is O or S,

R^(c) and R¹⁴ to R¹⁹ are independently hydrogen, deuterium, a halogen,germanium group, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted C1 to C10 alkyl group, asubstituted or unsubstituted C3 to C20 cycloalkyl group, a substitutedor unsubstituted C1 to C10 alkyl silyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group, and

n is an integer ranging from 1 to 3.

The organic optoelectronic device according to the present inventionincreases material stability by introducing a triazine or pyrimidinemoiety linked with dibenzofuran (or dibenzothiophene) and simultaneouslyintroducing a carbazole moiety to obtain additional stability due tobipolar characteristics as the first host. A glass transitiontemperature relative to a molecular weight due to the carbazole moietymay be improved and thus heat resistance may be ensured.

Particularly, indolocarbazole is combined as the second host and therebyholes and electrons are balanced to realize long life-span, low drivingvoltage characteristics.

Simultaneously, a phosphorescent dopant including a dibenzofuranylgroup, a dibenzothiophenyl group, or an N-containing analogous groupthereof is additionally combined and thereby combination matching suchas packing of host and dopant materials, energy transfer, and the likemay be ensured.

The first host represented by Chemical Formula 1 may be for examplerepresented by one of Chemical Formula 1-1 to Chemical Formula 1-4according to a specific linking position of dibenzofuran (ordibenzothiophene) with the nitrogen-containing hexagonal ring throughL².

In Chemical Formula 1-1 to Chemical Formula 1-4, X¹, Z¹ to Z³, L¹, L²,A, and R¹ to R⁴ are the same as described above.

In an example embodiment of the present invention, the first host may berepresented by Chemical Formula 1-3 or Chemical Formula 1-4, preferablyChemical Formula 1-3, and more preferably Chemical Formula 1-3a whereindibenzofuran (or dibenzothiophene) is directly linked with thenitrogen-containing hexagonal ring.

In Chemical Formula 1-3a, X¹, Z¹ to Z³, L¹, A, and R¹ to R⁴ are the sameas described above.

The first host increases a hole and electron injection rate through aLUMO expansion and a planarity expansion of an ET moiety such astriazine, pyrimidine, and the like by including a structure where3-dibenzofuran (or 3-dibenzothiophene) is directly linked with thetriazine or pyrimidine moiety as shown in Chemical Formula 1-3a andsecures additional stability and improves a glass transition temperaturerelative to a molecular weight and thus secures heat resistance byintroducing a carbazole moiety to apply bipolar characteristics.

In addition, indolocarbazole as a second host may be combined with thefirst host material to balance the first host material having fast andstable electron transport characteristics and the second host materialhaving fast and stable hole transport characteristics and thus to securea low driving/long life-span host set having a high glass transitiontemperature relative to a molecular weight.

Simultaneously, the host set may be combined with a phosphorescentdopant to secure a combination/matching advantage of packing of the hostand dopant materials, an energy transport, and the like and therebyobtain characteristics of a low driving, a long life-span, and highefficiency.

In an example embodiment of the present invention, the substituent A isa substituted or unsubstituted carbazolyl group, and may be representedby one of Chemical Formula A-1 to Chemical Formula A-5 according tospecifice substitution points.

In Chemical Formula A-1 to Chemical Formula A-5, R⁹ to R¹³ areindependently hydrogen, deuterium, a cyano group, a substituted orunsubstituted C1 to C10 alkyl group, or a substituted or unsubstitutedC6 to C20 aryl group, and * is a linking point with L¹.

In a specific example embodiment, R⁹ to R¹³ may independently behydrogen, or a substituted or unsubstituted C6 to C20 aryl group, andmore specifically R⁹ to R¹³ may independently be hydrogen or a phenylgroup,

for example when A is represented by Chemical Formula A-1, R⁹ to R¹² maybe all hydrogen or one or two of R⁹ to R¹² may be a phenyl group.

In addition, when A is represented by one of Chemical Formula A-2 toChemical Formula A-5, R¹³ may be a phenyl group and R¹⁰ to R¹² are allhydrogen or at least one of R¹¹ and R¹² may be a phenyl group.

Particularly, Chemical Formula 1-3a may be for example represented byone of Chemical Formula 1-3a-I, Chemical Formula 1-3a-II, ChemicalFormula 1-3a-III, Chemical Formula 1-3a-IV, and Chemical Formula 1-3a-V,and preferably Chemical Formula 1-3a-I, Chemical Formula 1-3a-II,Chemical Formula 1-3a-III, and Chemical Formula 1-3a-IV according tospecific structure of the substituent A.

In Chemical Formula 1-3a-I, Chemical Formula 1-3a-II, Chemical Formula1-3a-III, Chemical Formula 1-3a-IV and Chemical Formula 1-3a-V, X¹, Z¹to Z³, L^(t), R¹ to R⁴ and R⁹ to R¹³ are the same as described above.

On the other hand, in an example embodiment of the present invention,the hexagonal ring consisting of Z¹ to Z³ may be pyrimidine or triazine,in a specific example embodiment, pyrimidine where Z¹ and Z² are N,pyrimidine where Z¹ and Z³ are N, pyrimidine where Z² and Z³ are N, ortriazine where Z¹ to Z³ are N, and preferably triazine where Z¹ to Z³are N.

In an example embodiment of the present invention, R¹ may be asubstituted or unsubstituted phenyl group, a substituted orunsubstituted biphenyl group, a substituted or unsubstituted naphthylgroup, a substituted or unsubstituted dibenzofuranyl group, or asubstituted or unsubstituted dibenzothiophenyl group, and morespecifically R¹ may be a substituted or unsubstituted phenyl group, asubstituted or unsubstituted dibenzofuranyl group, or a substituted orunsubstituted dibenzothiophenyl group, and may be for example selectedfrom substituents of Group I.

In Group I, * is a linking point with a nitrogen-containing hexagonalring.

R¹ may be preferably a phenyl group, a dibenzofuranyl group, or adibenzothiophenyl group.

In an example embodiment of the present invention, R^(a) and R² to R⁴may independently be hydrogen, deuterium, a cyano group, or asubstituted or unsubstituted C6 to C12 aryl group, more specificallyR^(a) and R² to R⁴ may independently be hydrogen, deuterium, or a cyanogroup, and preferably R^(a) and R² to R⁴ may be all hydrogen.

In addition, in an example embodiment of the present invention, L¹ andL² may independently be a single bond, or a substituted or unsubstitutedC6 to C12 arylene group, and more specifically L¹ and L² mayindependently be a single bond, a meta-phenylene group, or apara-phenylene group.

In addition, in an example embodiment of the present invention, R⁹ toR¹¹ may independently be hydrogen, deuterium, a cyano group, or asubstituted or unsubstituted C6 to C12 aryl group, more specifically R⁹to R¹¹ may independently be hydrogen, deuterium, a cyano group or aphenyl group, and preferably R⁹ to R¹¹ are all hydrogen or at least oneof R⁹ to R¹¹ may be a phenyl group. More preferably, R⁹ to R¹¹ may beall hydrogen or one of R⁹ to R¹¹ may be a phenyl group.

The first host may be for example selected from compounds of Group 1,but is not limited thereto.

In an example embodiment of the present invention, the second host maybe for example represented by one of Chemical Formula 2A, ChemicalFormula 2B, Chemical Formula 2C, Chemical Formula 2D, and ChemicalFormula 2E, and in a specific example embodiment, the second host may befor example represented by one of Chemical Formula 2A, Chemical Formula2B, Chemical Formula 2C, and Chemical Formula 2D, and preferablyChemical Formula 2B according to a fusion position of Chemical Formula 2and Chemical Formula 3.

In Chemical Formula 2A to Chemical Formula 2E, Y¹ and Y², L³ and L⁴ andR⁵ to R⁸ are the same as described above, L^(a1) to L^(a4) are the sameas L^(a), and R^(b1) to R^(b4) are the same as R^(b).

On the other hand, in an example embodiment of the present invention,the Y¹ and Y² may independently be a substituted or unsubstituted phenylgroup, a substituted or unsubstituted biphenyl group, a substituted orunsubstituted pyridinyl group, a substituted or unsubstituted carbazolylgroup, a substituted or unsubstituted dibenzofuranyl group, or asubstituted or unsubstituted dibenzothiophenyl group, and in a specificexample embodiment, Y¹ and Y² may independently be a substituted orunsubstituted phenyl group, or a substituted or unsubstituted biphenylgroup, and preferably Y¹ and Y² may independently be a phenyl group or apara-biphenyl group.

In addition, in an example embodiment of the present invention, R^(b1)to R^(b4) and R⁵ to R⁸ may independently be hydrogen, deuterium, a cyanogroup, a substituted or unsubstituted phenyl group, a substituted orunsubstituted biphenyl group, a substituted or unsubstituted pyridinylgroup, a substituted or unsubstituted carbazolyl group, a substituted orunsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, in a specific example embodiment, R^(b1) toR^(b4) may independently be hydrogen, deuterium, a cyano group, asubstituted or unsubstituted phenyl group, a substituted orunsubstituted biphenyl group, a substituted or unsubstituted pyridinylgroup, a substituted or unsubstituted carbazolyl group, a substituted orunsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group and R⁵ to R⁸ may independently be hydrogen,deuterium, a cyano group, a substituted or unsubstituted phenyl group,or a substituted or unsubstituted biphenyl group, and in more specificexample embodiment, R^(b1) to R^(b4) and R⁵ to R⁸ may be all hydrogen.

Y¹, Y², R^(b1) to R^(b4), and R⁵ to R⁸ may be for example selected fromsubstituents of Group II.

In Group II, * is a linking point.

In addition, in an example embodiment of the present invention, L^(a1)to L^(a4) and L³ and L⁴ may independently be a single bond, asubstituted or unsubstituted para-phenylene group, a substituted orunsubstituted meta-phenylene group, or a substituted or unsubstitutedbiphenylene group, and in a specific example embodiment, L^(a1) toL^(a4) and L³ and L⁴ may independently be a single bond, a substitutedor unsubstituted para-phenylene group, or a substituted or unsubstitutedmeta-phenylene group, and preferably L^(a1) to L^(a4) and L³ and L⁴ mayindependently be a single bond or a para-phenylene group.

The second host may be for example selected from compounds of Group 2,but is not limited thereto.

The first host and the second host may be applied as a form of acomposition.

In an example embodiment of the present invention, the first hostapplied to the composition may be represented by Chemical Formula 1-3aand the second host may be represented by Chemical Formula 2B.

Z¹ to Z³ of Chemical Formula 1-3a may be all N, R¹ is a substituted orunsubstituted C6 to C20 aryl group, a substituted or unsubstituteddibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, and L¹ may be a single bond or a meta-phenylenegroup, and

Y¹ and Y² of Chemical Formula 2B may independently be a substituted orunsubstituted C6 to C20 aryl group, and L³ and L⁴ may independently be asubstituted or unsubstituted C6 to C20 arylene group.

The first host and the second host in the present invention may be aknown phosphorescent dopant that is an organometal compound includingone of Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd, or acombination thereof or may be mixed with an organometal compoundrepresented by Chemical Formula 401. However, these are exemplified, anda dopant that exhibit excellent effect by combining the composition ofthe first host and the second host according to the present invention isa phosphorescent dopant represented by Chemical Formula 4.

In Chemical Formula 401, M is selected from Ir, Pt, Os, Ti, Zr, Hf, Eu,Tb, and Tm; X₄₀₁ to X₄₀₄ are independently nitrogen or carbon; A₄₀₁ andA₄₀₂ rings are independently selected from a substituted orunsubstituted benzene, a substituted or unsubstituted naphthalene, asubstituted or unsubstituted fluorene, a substituted or unsubstitutedspiro-fluorene, a substituted or unsubstituted indene, a substituted orunsubstituted pyrrole, a substituted or unsubstituted thiophene, asubstituted or unsubstituted furan, a substituted or unsubstitutedimidazole, a substituted or unsubstituted pyrazole, a substituted orunsubstituted thiazole, a substituted or unsubstituted isothiazole, asubstituted or unsubstituted oxazole, a substituted or unsubstitutedisoxazole, a substituted or unsubstituted pyridine, a substituted orunsubstituted pyrazine, a substituted or unsubstituted pyrimidine, asubstituted or unsubstituted pyridazine, a substituted or unsubstitutedquinoline, a substituted or unsubstituted isoquinoline, a substituted orunsubstituted benzoquinoline, a substituted or unsubstitutedquinoxaline, a substituted or unsubstituted quinazoline, a substitutedor unsubstituted carbazole, a substituted or unsubstitutedbenzoimidazole, a substituted or unsubstituted benzofuran, a substitutedor unsubstituted benzothiophene, a substituted or unsubstitutedisobenzothiophene, a substituted or unsubstituted benzooxazole, asubstituted or unsubstituted isobenzooxazole, a substituted orunsubstituted triazole, a substituted or unsubstituted oxadiazole, asubstituted or unsubstituted triazine, a substituted or unsubstituteddibenzofuran, and a substituted or unsubstituted dibenzothiophene;wherein “substituted” refers to replacement of at least one hydrogen ofa substituent or a compound by deuterium, a halogen, a hydroxyl group, acyano group, an amino group, a substituted or unsubstituted C1 to C30amine group, a nitro group, a substituted or unsubstituted C1 to C40silyl group, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6to C30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heterocyclicgroup, a C1 to C20 alkoxy group, a C1 to C10 trifluoroalkyl group, or acombination thereof; L₄₀₁ is an organic ligand; xc1 is 1, 2, or 3; andxc2 is 0, 1, 2, or 3.

L₄₀₁ may be any monovalent, divalent, or trivalent organic ligand. Forexample, L₄₀₁ may be selected from a halogen ligand (for example, C1,F), diketone ligand (for example, acetylacetonate,1,3-diphenyl-1,3-propanedionate, 2,2,6,6-tetramethyl-3,5-heptanedionate,or hexafluoroacetonate), carboxylic acid ligand (for example,picolinate, dimethyl-3-pyrazolecarboxylate, benzoate), a carbonmonooxide ligand, an isonitrile ligand, a cyano ligand, and a phosphorusligand (for example, phosphine, phosphite), but is not limited thereto.

Q₄₀₁ to Q₄₀₇, Q₄₁₁ to Q₄₁₇, and Q₄₂₁ to Q₄₂₇ may independently beselected from hydrogen, a C1 to C60 alkyl group, a C2 to C60 alkenylgroup, a C6 to C60 aryl group, and a C2 to C60 heteroaryl group.

When A₄₀₁ of Chemical Formula 401 has two or more substituents, they maybe combined with two or more substituents of A₄₀₁ to form a saturated orunsaturated ring.

When A₄₀₂ of Chemical Formula 401 has two or more substituents, they maybe combined with two or more substituents of A₄₀₂ to form a saturated orunsaturated ring.

When xc1 of Chemical Formula 401 is two or more, a plurality of ligands

of Chemical Formula 401 may be the same or different. When xc1 ofChemical Formula 401 is two or more, A₄₀₁ and A₄₀₂ may be independentlylinked with A₄₀₁ and A₄₀₂ of adjacent other ligand directly or by alinking group(for example, C1 to C5 alkylene group, —N(R′)— (wherein, R′is a C1 to C10 alkyl group or a C6 to C20 aryl group), or —C(═O)—).

That is, in an example embodiment of the present invention, anorganometal compound represented by Chemical Formula 4 is used.

In Chemical Formula 4,

Z⁴ to Z¹¹ are independently N, C or CR^(c),

the ring C is bound to the ring B through a C—C bond,

iridium is bound to the ring B through a Ir—C bond,

X² is O or S,

R^(c) and R¹⁴ to R¹⁹ are independently hydrogen, deuterium, a halogen,germanium group, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted C1 to C10 alkyl group, asubstituted or unsubstituted C3 to C20 cycloalkyl group, a substitutedor unsubstituted C1 to C10 alkylsilyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group, and

n is an integer ranging from 1 to 3.

The composition including the first and second hosts may be combinedwith the phosphorescent dopant including a dibenzofuranyl group, adibenzothiophenyl group, or derivative groups thereof including at leastone N to secure a combination/matching advantage of packing of host anddopant materials, an energy transport, and the like and thus obtaincharacteristics of a low driving, a long life-span, and high efficiency.

In an example embodiment of the present invention, in Chemical Formula4, one of Z⁴ to Z¹¹ may be preferably N, and two, three, or four may beN.

The phosphorescent dopant may be for example represented by one ofChemical Formula 4-1 to Chemical Formula 4-6.

In Chemical Formula 4-1 to Chemical Formula 4-6, X², R¹⁴ to R¹⁹ and nare the same as described above, and R^(c1), R^(c2), and R^(c3) are thesame as.

In a specific example embodiment of the present invention, R^(c),R^(c1), R^(c2), R^(c3) and R¹⁴ to R¹⁹ may independently be hydrogen,deuterium, a halogen, a substituted or unsubstituted silyl group, asubstituted or unsubstituted C1 to C10 alkyl group, a substituted orunsubstituted C1 to C10 alkylsilyl group, or a substituted orunsubstituted C6 to C20 aryl group, for example R^(c), R^(c1), R^(c2),R^(c3) and R¹⁴ to R¹⁹ may independently be hydrogen, deuterium, ahalogen, a substituted or unsubstituted silyl group, a substituted orunsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1to C10 alkylsilyl group, or a substituted or unsubstituted C6 to C12aryl group, and preferably R^(c), R^(c1), R^(c2), R^(c3) and R¹⁴ to R¹⁹may independently be hydrogen, deuterium, a halogen, a silyl group thatis substituted or unsubstituted with deuterium or a halogen, a methylgroup that is substituted or unsubstituted with deuterium or a halogen,an isopropyl group that is substituted or unsubstituted with deuteriumor a halogen, a tert-butyl group that is substituted or unsubstitutedwith deuterium or a halogen, or a silyl group that is substituted orunsubstituted with a C1 to C4 alkyl group.

The phosphorescent dopant may be for example selected from compounds ofGroup 3, but is not limited thereto.

In a more preferably example embodiment of the present invention, acomposition including a first host represented by Chemical Formula 1-3a,a second host represented by Chemical Formula 2B, and a phosphorescentdopant represented by Chemical Formula 4-1 may be applied to the lightemitting layer, and

Z¹ to Z³ of Chemical Formula 1-3a may be all N, R¹ may be a substitutedor unsubstituted C6 to C20 aryl group, a substituted or unsubstituteddibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, L¹ may be a single bond or a meta-phenylenegroup,

Y¹ and Y² of Chemical Formula 2B may independently be a substituted orunsubstituted C6 to C20 aryl group and L³ and L⁴ may independently be asubstituted or unsubstituted C6 to C20 arylene group, and

R^(c1), R^(c2), R^(c3) and R¹⁴ to R¹⁹ of Chemical Formula 4-1 mayindependently be hydrogen, deuterium, a halogen, a substituted orunsubstituted silyl group, a substituted or unsubstituted C1 to C10alkyl group, a substituted or unsubstituted C1 to C10 alkylsilyl group,or a substituted or unsubstituted C6 to C12 aryl group.

More specifically, the first host and the second host may be included ina weight ratio of 1:9 to 6:4, 2:8 to 6:4, 3:7 to 6:4, more preferably,the first host and the second host may be included in a weight ratio of1:9 to 5:5, 2:8 to 5:5, 3:7 to 5:5, and the most preferably the firsthost and the second host may be included in a weight ratio of 4:6 to5:5.

The phosphorescent dopant may be included in an amount of about 0.1 wt %to 15 wt %, preferably 1 wt % to 15 wt %, and more preferably 5 wt % to15 wt % based on 100 wt % of the composition of the first host andsecond host. For example, the first host and the second host may beincluded in a weight ratio of 3:7 and the phosphorescent dopant may beincluded in an amount of 5 wt % to 15 wt % based on 100 wt % of thecomposition of the first host and second host.

The organic light emitting diode may be applied to an organic lightemitting diode (OLED) display.

Embodiments of the Invention

Hereinafter, the embodiments are illustrated in more detail withreference to examples. These examples, however, are not in any sense tobe interpreted as limiting the scope of the invention.

Hereinafter, starting materials and reactants used in Examples andSynthesis Examples were purchased from Sigma-Aldrich Co. Ltd. or TCIInc. as far as there in no particular comment or were synthesized byknown methods.

The compound as one specific examples of the present invention wassynthesized through the following steps.

Preparation of First Host Synthesis Example 1: Synthesis of Compound B-1

a) Synthesis of Intermediate B-1-1

30.0 g (64.2 mmol) of 2,4-bis(3-bromophenyl)-6-phenyl-1,3,5-triazinewere added to 100 mL of tetrahydrofuran, 100 mL of toluene, and 100 mLof distilled water in a 500 mL round-bottomed flask, 1.0 equivalent ofdibenzofuran-4-boronic acid, 0.03 equivalent oftetrakistriphenylphosphine palladium, and 2 equivalents of potassiumcarbonate were added thereto, and the mixture was heated and refluxedunder a nitrogen atmosphere. After 6 hours, the reaction solution wascooled down, an aqueous layer was removed, and an organic layer wasdried under a reduced pressure. The obtained solid was washed with waterand hexane, the solid was recrystallized with 300 mL of toluene toobtain 21.4 g (60% yield) of Intermediate B-1-1.

b) Synthesis of Intermediate B-1-2

15 g (46.55 mmol) of 4-bromo-9-phenylcarbazole (cas: 1097884-37-1) wasadded to 200 mL of toluene in a 500 mL round-bottomed flask, 0.05equivalent of dichlorodiphenylphosphinoferrocene palladium, 1.2equivalent of bis(pinacolato) diboron, and 2 equivalents of potassiumacetate were added thereto, and the mixture was heated and refluxedunder a nitrogen atmosphere for 18 hours. The reaction solution wascooled down and added to 1 L of water in a dropwise fashion. A solidobtained therefrom was dissolved in boiling toluene to treat activatedcarbon and then, filtered with silica gel, and a filtrate therefrom wasconcentrated. The concentrated solid was stirred with a small amount ofhexane and filtered to obtain Intermediate B-1-2 at a yield of 80%.

c) Synthesis of Compound B-1

20 g (36.1 mmol) of Intermediate B-1-1 was added to 100 mL oftetrahydrofuran and 50 mL of distilled water in a 500 mL round-bottomedflask, 1.1 equivalent of Intermediate B-1-2, 0.03 equivalent oftetrakistriphenylphosphine palladium, and 2 equivalents of potassiumcarbonate were added thereto, and the mixture was heated and refluxedunder a nitrogen atmosphere. After 18 hours, the reaction solution wascooled down, and a solid precipitated therein was filtered and washedwith 500 mL of water. The solid was recrystallized with 500 mL ofmonochlorobenzene to obtain 24 g of Compound B-1.

LC/MS calculated for: C51H32N4O Exact Mass: 716.2576 found for: 717.26[M+H]

Synthesis Example 2: Synthesis of Compound B-13

1 equivalent of Intermediate B-1-1, 1 equivalent of carbazole, 2 eq ofsodium t-butoxide, and 0.05 eq of Pd₂(dba)₃ were suspended to be 0.2M inxylene, 0.15 eq of tri-tertiarybutylphosphine was added thereto, and themixture was refluxed and stirred for 18 hours. Methanol was addedthereto in 1.5 times as much as the solvent, the mixture was stirred,and a solid obtained therefrom was filtered and washed with 300 mL ofwater. The solid was recrystallized by using monochlorobenzene to obtainCompound B-13 at a yield of 85%.

LC/MS calculated for: C45H28N4O Exact Mass: 640.2263 found for: 641.23[M+H]

Synthesis Example 3: Synthesis of Compound B-17

a) Synthesis of Intermediate B-17-1

15 g (46.4 mmol) of 4-(3-bromophenyl)-dibenzofuran (cas: 887944-90-3)was added to 200 mL of toluene in a 500 mL round-bottomed flask, 0.05equivalent of dichlorodiphenylphosphinoferrocene palladium, 1.2equivalent of bis(pinacolato) diboron, and 2 equivalents of potassiumacetate were added thereto, and the mixture was heated and refluxedunder an nitrogen atmosphere for 18 hours. The solution was washed withwater through an extraction, an organic layer therefrom was treated withactivated carbon and filtered in silica gel, and a filtrate wasconcentrated. The concentrated solid was stirred with an amount ofhexane and filtered to obtain Intermediate B-17-1 at a yield of 85%.

b) Synthesis of Intermediate B-17-2

9.04 g (40 mmol) of 2,4-dichloro-6-phenyltriazine was added to 60 mL oftetrahydrofuran, 60 mL of toluene, and 60 mL of distilled water in a 500mL round-bottomed flask, 0.9 equivalent of Intermediate B-17-1, 0.03equivalent of tetrakistriphenylphosphine palladium, and 2 equivalents ofpotassium carbonate were added thereto, and the mixture was heated andrefluxed under a nitrogen atmosphere. After 6 hours, the reactionsolution was cooled down, and after removing an aqueous layer therefrom,an organic layer therein was dried under a reduced pressure. A solidtherefrom was washed with water and hexane and then, recrystallized with300 mL of toluene to obtain Intermediate B-17-2 at a yield of 40%.

c) Synthesis of Compound B-17

1 equivalent of Intermediate B-17-2, 1.1 equivalent of carbazole, 2 eqof sodium t-butoxide, and 0.05 eq of Pd₂(dba)₃ were suspended to be 0.2Min xylene, 0.15 eq of tri-tertiarybutylphosphine was added thereto, andthe mixture was refluxed and stirred for 18 hours. Methanol was addedthereto 1.5 times as much as the solvent, and a solid therein wasfiltered and washed with 300 mL of water. The solid was recrystallizedby using monochlorobenzene to obtain Compound B-17 at a yield of 80%.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.21[M+H]

Synthesis Example 4: Synthesis of Compound C-1

a) Synthesis of Intermediate C-1-1

22.6 g (100 mmol) of 2,4-dichloro-6-phenyltriazine was added to 100 mLof tetrahydrofuran, 100 mL of toluene, and 100 mL of distilled water ina 500 mL round-bottomed flask, 0.9 equivalent of dibenzofuran-3-boronicacid, 0.03 equivalent of tetrakistriphenylphosphine palladium, and 2equivalents of potassium carbonate were added thereto, and the mixturewas heated and refluxed under a nitrogen atmosphere. After 6 hours, thereaction solution was cooled down, and after removing an aqueous layertherefrom, an organic layer therein was dried under a reduced pressure.The obtained solid was washed with water and hexane and recrystallizedwith 200 mL of toluene to obtain 21.4 g of Intermediate C-1-1 at a yieldof 60%.

b) Synthesis of Compound C-1-2

15 g (46.55 mmol) of 4-bromo-9-phenylcarbazole (cas: 1097884-37-1) wasadded to 140 mL of tetrahydrofuran and 70 mL of distilled water in a 500mL round-bottomed flask, 1.1 equivalent of 3-chlorophenyl boronic acid,0.03 equivalents of tetrakistriphenylphosphine palladium, and 2equivalents of potassium carbonate were added thereto, and the mixturewas heated and refluxed under a nitrogen atmosphere. After 12 hours, thereaction solution was cooled down, an organic layer was extracted toremove a solvent under a reduced pressure. A compound concentratedtherefrom was treated through silica column chromatography to obtainIntermediate C-1-2 at a yield of 85%.

c) Synthesis of Intermediate C-1-3

12 g (33.9 mmol) of Intermediate C-1-2 was added to 150 mL of xylene ina 500 mL round-bottomed flask, 0.05 equivalent ofdichlorodiphenylphosphinoferrocene palladium, 1.2 equivalent ofbis(pinacolato) diboron, and 2 equivalents of potassium acetate wereadded thereto, and the mixture was heated and refluxed under a nitrogenatmosphere for 18 hours. The reaction solution was cooled down and then,washed with water through an extraction, an organic layer therefrom wastreated with activated carbon and filtered in silica gel, and a filtratetherefrom was concentrated. A solid concentrated therefrom was stirredwith a small amount of hexane and filtered to obtain Intermediate C-1-3at a yield of 75%.

d) Synthesis of Compound C-1

8 g (22.4 mmol) of Intermediate C-1-1 was added to 80 mL oftetrahydrofuran and 40 mL of distilled water in a 500 mL round-bottomedflask, 1.0 equivalent of Intermediate C-1-3, 0.03 equivalent oftetrakistriphenylphosphine palladium, and 2 equivalents of potassiumcarbonate were added thereto, and the mixture was heated and refluxedunder a nitrogen atmosphere. After 18 hours, the reaction solution wascooled down, and a solid precipitated therein was filtered and washedwith 500 mL of water. The solid was recrystallized with 500 mL ofmonochlorobenzene to obtain 12 g of Compound C-1.

LC/MS calculated for: C45H28N4O Exact Mass: 640.2263 found for: 641.24

Synthesis Example 5: Synthesis of Compound C-2

a) Synthesis of Intermediate C-2-1

15 g (46.4 mmol) of 3-(3-bromophenyl)-9-phenylcarbazole (cas:854952-59-3) was added to 200 mL of toluene in a 500 mL round-bottomedflask, 0.05 equivalent of dichlorodiphenylphosphinoferrocene palladium,1.2 equivalent of bis(pinacolado) diboron, and 2 equivalents ofpotassium acetate were added thereto, and the mixture was heated andrefluxed under a nitrogen atmosphere for 18 hours. The reaction solutionwas cooled down and added to 1 L of water in a dropwise fashion tocollect a solid. The solid was dissolved in boiling toluene to treatactivated carbon and filtered in silica gel, and a filtrate therefromwas concentrated. The concentrated solid was stirred with a small amountof hexane and filtered to obtain Intermediate C-2-1 at a yield of 85%.

b) Synthesis of Compound C-2

8 g (22.4 mmol) of Intermediate C-1-1 according to Synthesis Example 4was added to 80 mL of tetrahydrofuran and 40 mL of distilled water in a500 mL round-bottomed flask, 1.0 equivalent of Intermediate C-2-1, 0.03equivalent of tetrakistriphenylphosphine palladium, and 2 equivalents ofpotassium carbonate were added thereto, and the mixture was heated andrefluxed under a nitrogen atmosphere. After 18 hours, the reactionsolution was cooled down, and a solid precipitated therein was washedwith 500 mL of water. The solid was recrystallized by using 500 mL ofmonochlorobenzene to obtain 13 g of Compound C-1.

LC/MS calculated for: C45H28N4O Exact Mass: 640.2263 found for: 641.24

Synthesis Example 6: Synthesis of Compound C-12

8 g (22.4 mmol) of Intermediate C-1-1 according to Synthesis Example 4was added to 80 mL of tetrahydrofuran and 40 mL of distilled water in a500 mL round-bottomed flask, 1.0 equivalent of9-phenyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-carbazole (cas:1246669-45-3), 0.03 equivalent of tetrakistriphenylphosphine palladium,and 2 equivalents of potassium carbonate were added thereto, and themixture was heated and refluxed under a nitrogen atmosphere. After 18hours, the reaction solution was cooled down, and a solid precipitatedtherein was filtered and washed with 500 mL of water. The solid wasrecrystallized with 500 mL of monochlorobenzene to obtain 11 g ofCompound C-12.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Synthesis Example 7: Synthesis of Compound C-16

a) Synthesis of Intermediate C-16-1

Magnesium (7.86 g, 323 mmol) and iodine (1.64 g, 6.46 mmol) were addedto 0.1 L of tetrahydrofuran (THF) in a nitrogen environment, the mixturewas stirred for 30 minutes, and 3-bromo dibenzofuran (80 g, 323 mmol)dissolved in 0.3 L of THF was slowly added thereto in a dropwise fashionat 0° C. over 30 minutes. The mixed solution was slowly added in adropwise fashion to 29.5 g (160 mmol) of cyanuric chloride dissolved in0.5 L of THE at 0° C. over 30 minutes. After heating a reaction up toroom temperature, the mixture was stirred for 1 hour and additionallystirred for 12 hours under a reflux condition. After cooling down thereaction, water was slowly added thereto to finish the reaction, and anorganic solvent therefrom was concentrated under a reduced pressure toobtain a solid. The solid was stirred with 200 mL of acetone andfiltered to obtain Intermediate C-16-1 at a yield of 40%.

b) Synthesis of Compound C-16

Compound C-16 was synthesized according to the same method as SynthesisExample 2 by using Intermediate C-16-1.

LC/MS calculated for: C39H22N4O2 Exact Mass: 578.1743 found for 579.20

Synthesis Example 8: Synthesis of Compound C-17

Compound C-17 was synthesized according to the same method as SynthesisExample 2 by using Intermediate C-1-1 and 3-phenyl-9H-carbazolerespectively by 1 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Synthesis Example 9: Synthesis of Compound C-21

Compound C-21 was synthesized according to the same method as SynthesisExample 6 by using Intermediate C-1-1 and9-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)-carbazole(cas:785051-54-9) respectively by 1.0 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Synthesis Example 10: Synthesis of Compound C-22

Compound C-22 was synthesized according to the same method as SynthesisExample 6 by using Intermediate C-1-1 and9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)-carbazole(cas: 870119-58-7) respectively by 1.0 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Synthesis Example 11: Synthesis of Compound C-25

a) Synthesis of Intermediate C-25-1

Intermediate C-25-1 was synthesized according to the same method asSynthesis Example 2 by using 1 equivalent of 3-phenyl-9H-carbazole and1.2 equivalent of 3-chloro-1-bromobenzene.

b) Synthesis of Intermediate C-25-2

Intermediate C-25-2 was synthesized according to the same method as a)of Synthesis Example 5 by using Intermediate C-25-1.

c) Synthesis of Compound C-25

Intermediate C-25 was synthesized according to the same method as a) ofSynthesis Example 6 by using Intermediate C-25-2 and Intermediate C-1-1respectively by 1.0 equivalent.

LC/MS calculated for: C45H28N4O Exact Mass: 640.2263 found for: 641.23

Synthesis Example 12: Synthesis of Compound B-14

a) Synthesis of Intermediate B-14-1

Intermediate B-14-1 was synthesized according to the same method as a)of Synthesis Example 4 by using 1 equivalent of2,4-dichloro-6-phenyltriazine and 0.9 equivalent ofdibenzofuran-4-boronic acid.

b) Synthesis of Compound B-14

Intermediate B-14 was synthesized according to the same method asSynthesis Example 6 by using Intermediate B-14-1 and9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)-carbazole(cas: 870119-58-7) by respectively 1.0 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Synthesis Example 13: Synthesis of Compound B-22

a) Synthesis of Intermediate B-22-1

Intermediate B-22-1 was synthesized according to the same method as a)of Synthesis Example 4 by using 1 equivalent of2,4-dichloro-6-phenyltriazine and 0.9 equivalent ofdibenzofuran-2-boronic acid.

b) Synthesis of Compound B-22

Compound B-22 was synthesized according to the same method as SynthesisExample 6 by using Intermediate B-22-1 and9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)-carbazole(cas: 870119-58-7) respectively by 1.0 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.21

Synthesis Example 14: Synthesis of Compound B-25

a) Synthesis of Intermediate B-25-1

Intermediate B-25-1 was synthesized according to the same method as a)of Synthesis Example 4 by using 1 equivalent of2,4-dichloro-6-phenyltriazine and 0.9 equivalent ofdibenzofuran-1-boronic acid.

b) Synthesis of Compound B-25

Compound B-25 was synthesized according to the same method as SynthesisExample 6 by using Intermediate B-25-1 and9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)-carbazole(cas: 870119-58-7) respectively by 1.0 equivalent.

LC/MS calculated for: C39H24N4O Exact Mass: 564.1950 found for: 565.20

Preparation of Second Host

Synthesis Example 15: Synthesis of Compound D-1

Compound D-1 was synthesized according to the same method as SynthesisExample 2 by using 1 equivalent of a synthesis intermediate,5,7-dihydro-indolo[2,3-b]carbazole (cas: 111296-90-3) and 2.5equivalents of 4-bromo-1,1′-biphenyl (cas:92-66-0).

LC/MS calculated for: C42H28N2 Exact Mass: 560.2252 found for: 561.24

Synthesis Examples 16 to 18: Synthesis of Compound D-21, Compound D-41and Compound D-72

Compound D-21, Compound D-41, and Compound D-72 were synthesizedaccording to the same method as the synthesis method of Compound D-1 ofSynthesis Example 15 by intermediates11,12-dihydro-indolo[2,3-a]carbazole (cas: 60511-85-5),5,8-dihydro-indolo[2,3-c]carbazole (cas: 200339-30-6),5,12-dihydro-indolo[3,2-a]carbazole (cas: 111296-91-4), respectively.

Preparation of Phosphorescent Dopant Synthesis Example 19: Synthesis ofCompound E-24

Dopant Compound E-24 was prepared through the same reaction as aboveexcept for using an indium complex described [Reaction Scheme 16] as astarting material in a method of manufacturing Compound II-1 ofUS2014-0131676.

(Manufacture of Organic Light Emitting Diode)

Example 1

A glass substrate coated with ITO (indium tin oxide) as a 1500 Å-thickthin film was washed with distilled water. After washing with thedistilled water, the glass substrate was ultrasonic wave-washed with asolvent such as isopropyl alcohol, acetone, methanol, and the like anddried and then, moved to a plasma cleaner, cleaned by using oxygenplasma for 10 minutes, and moved to a vacuum depositor. This obtainedITO transparent electrode was used as an anode, Compound A wasvacuum-deposited on the ITO substrate to form a 700 Å-thick holeinjection layer, Compound B was deposited to be 50 Åthick on theinjection layer, and Compound C was deposited to be 1020 Åthick to forma hole transport layer. On the hole transport layer, a 400 Å-thick lightemitting layer was formed by vacuum-depositing Compound C-1 as a firsthost and Compound D-1 as a second host and 10 wt % of E-24 as aphosphorescent dopant. Herein Compound C-1 and Compound D-1 were used ina weight ratio of 4:6, but their ratio in the following Examples wasseparately provided. Subsequently, on the light emitting layer, a 300Å-thick electron transport layer was formed by simultaneouslyvacuum-depositing the compound D and Liq in a ratio of 1:1, and on theelectron transport layer, Liq and Al were sequentially vacuum-depositedto be 15 Åthick and 1200 Åthick, manufacturing an organic light emittingdiode.

The organic light emitting diode had a five-layered organic thin layer,and specifically a structure of ITO/Compound A (700 Å)/Compound B (50Å)/Compound C (1020 Å)/EML[Compound C-1: Synthesis of Compound D-1:Synthesis of Compound E-24 (10 wt %)] (400 Å)/Compound D: Liq (300Å)/Liq (15 Å)/Al (1200 Å).

Compound A:N4,N4′-diphenyl-N4,N4′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine

Compound B: 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN),

Compound C:N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine

Compound D:8-(4-(4,6-di(naphthalen-2-yl)-1,3,5-triazin-2-yl)phenyl)quinolone

Examples 2 to Example 24 and Comparative Examples 1 to 6

Each organic light emitting diodes was manufactured according to thesame method as Example 1 except for changing the composition of thefirst host, the second host, and the phosphorescent dopant into eachcomposition shown in Table 1.

Evaluation 1: Luminous Efficiency and Life-span Increase Effect

Luminous efficiency and life-span characteristics of the organic lightemitting diodes according to Examples 1 to 24 and Comparative Examples 1to 6 were evaluated. The measurements were specifically performed in thefollowing methods, and the results are shown in Table 1.

(1) Measurement of Current Density Change Depending on Voltage Change

The obtained organic light emitting diodes were measured regarding acurrent value flowing in the unit device, while increasing the voltagefrom 0 V to 10 V using a current-voltage meter (Keithley 2400), and, themeasured current value was divided by area to provide the results.

(2) Measurement of Luminance Change Depending on Voltage Change

Luminance was measured by using a luminance meter (Minolta Cs-1000A),while the voltage of the organic light emitting diodes was increasedfrom 0 V to 10 V.

(3) Measurement of Luminous Efficiency

Current efficiency (cd/A) at the same current density (10 mA/cm²) werecalculated by using the luminance, current density, and voltages (V)from the items (1) and (2).

(4) Measurement of Life-span

T90 life-spans of the organic light emitting diodes according toExamples 1 to 24 and Comparative Examples 1 to 6 were measured as a timewhen their luminance decreased down to 90% relative to the initialluminance (cd/m²) after emitting light with 5000 cd/m² as the initialluminance (cd/m²) and measuring their luminance decrease depending on atime with a Polanonix life-span measurement system.

(5) Measurement of Driving Voltage

A driving voltage of each diode was measured using a current-voltagemeter (Keithley 2400) at 15 mA/cm².

TABLE 1 Device results Ratio of first Second and second EfficiencyLife-span Driving First host host hosts Dopant Color Cd/A T90 (Vd)Comparative C-1 — alone E-24 green 56 30 4.1 Example 1 Comparative C-1CBP 4:6 E-24 green 61 60 4.8 Example 2 Example 1 C-1 D-1 4:6 E-24 green67 580 3.7 Comparative C-1 D-1 4:6 Ir(ppy)₃ green 48 160 4.2 Example 3Comparative C-22 — alone E-24 green 53 40 4.0 Example 4 Comparative C-22CBP 4:6 E-24 green 60 80 4.7 Example 5 Example 2 C-22 D-1 4:6 E-24 green68 620 3.7 Comparative C-22 D-1 4:6 Ir(ppy)₃ green 49 190 4.2 Example 6Example 3 C-1 D-21 4:6 E-24 green 63 270 4.3 Example 4 C-22 D-21 4:6E-24 green 65 350 4.4 Example 5 C-1 D-41 4:6 E-24 green 65 490 3.5Example 6 C-22 D-41 4:6 E-24 green 66 520 3.5 Example 7 C-1 D-72 4:6E-24 green 69 520 3.8 Example 8 C-22 D-72 4:6 E-24 green 67 560 3.8Example 9 C-2 D-1 4:6 E-24 green 70 590 3.8 Example 10 C-12 D-1 4:6 E-24green 64 480 3.5 Example 11 C-16 D-1 4:6 E-24 green 65 620 3.6 Example12 C-17 D-1 4:6 E-24 green 67 570 3.7 Example 13 C-21 D-1 4:6 E-24 green64 550 3.7 Example 14 C-22 D-1 4:6 E-24 green 68 600 3.8 Example 15 C-25D-1 4:6 E-24 green 69 630 3.8 Example 16 B-1 D-1 4:6 E-24 green 68 3804.0 Example 17 B-13 D-1 4:6 E-24 green 67 250 4.1 Example 18 B-17 D-14:6 E-24 green 67 330 3.9 Example 19 B-14 D-1 4:6 E-24 green 65 350 4.0Example 20 B-22 D-1 4:6 E-24 green 64 210 4.2 Example 21 B-25 D-1 4:6E-24 green 62 230 4.1 Example 22 B-14 D-72 4:6 E-24 green 66 440 4.1Example 23 B-22 D-72 4:6 E-24 green 63 250 4.4 Example 24 B-25 D-72 4:6E-24 green 64 290 4.3

Referring to Table 1, when a material including DBX and carbazole wasused as a first host, and indolocarbazole was used as a second host, anadvantage in terms of driving and life-span was obtained, compared withwhen the first host was used alone or when CBP was used as the secondhost. In addition, when Ir(ppy)₃ as a phosphorescent dopant notincluding a DBX bone was used, a life-span and efficiency were largelyincreased, compared with when Compound E-24 as a phosphorescent dopantincluding a DBX bone was used. Particularly, when the structure ofdirectly linking a position No. 3 of dibenzofuran with triazine as thefirst host was used, an effect of additionally decreasing a drivingvoltage but additionally increasing a life-span was obtained.

While this invention has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims. Therefore, the aforementioned embodimentsshould be understood to be exemplary but not limiting the presentinvention in any way.

DESCRIPTION OF SYMBOLS

-   -   100, 200: organic light emitting diode    -   105: organic layer    -   110: cathode    -   120: anode    -   130: light emitting layer    -   140: hole auxiliary layer

What is claimed is:
 1. An organic optoelectronic device, comprising: ananode and a cathode facing each other; and an organic layer disposedbetween the anode and the cathode, wherein the organic layer includes atleast one of a hole injection layer, a hole transport layer, a lightemitting layer, and an electron transport layer, wherein the lightemitting layer includes a first host represented by Chemical Formula1-3a-II, Chemical Formula 1-3a-III, Chemical Formula 1-3a-IV, orChemical Formula 1-3a-V, a second host represented by a combination ofChemical Formula 2 and Chemical Formula 3, and a phosphorescent dopantrepresented by Chemical Formula 4,

wherein, in Chemical Formula 1-3a-II, Chemical Formula 1-3a-III,Chemical Formula 1-3a-IV, and Chemical Formula 1-3a-V, X¹ is O or S, Z¹to Z³ are independently N or CR^(a), at least two of Z¹ to Z³ are N, L¹is a single bond, or a substituted or unsubstituted C6 to C20 arylenegroup, R¹ is a substituted or unsubstituted C6 to C20 aryl group, asubstituted or unsubstituted dibenzofuranyl group, or a substituted orunsubstituted dibenzothiophenyl group, and R^(a), R² to R⁴, and R¹⁰ toR¹³ are independently hydrogen, deuterium, a cyano group, a substitutedor unsubstituted C1 to C10 alkyl group, or a substituted orunsubstituted C6 to C20 aryl group; wherein, in Chemical Formula 2 andChemical Formula 3, Y¹ and Y² are independently a substituted orunsubstituted phenyl group, a substituted or unsubstituted biphenylgroup, a substituted or unsubstituted carbazolyl group, a substituted orunsubstituted dibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group, adjacent two *'s of Chemical Formula 2 arelinked with Chemical Formula 3, * of Chemical Formula 2 that are notlinked with Chemical Formula 3 are independently C-L^(a)-R^(b), L^(a),L³, and L⁴ are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group, R^(b) and R⁵ to R⁸ areindependently hydrogen, deuterium, a cyano group, a substituted orunsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6to C20 aryl group, or a substituted or unsubstituted C2 to C30heterocyclic group; wherein, in Chemical Formula 4, Z⁴ to Z¹¹ areindependently N, C or CR^(c), the ring C is bound to the ring B througha C—C bond, iridium is bound to the ring B through a Ir—C bond, X² is Oor S, R^(c) and R¹⁴ to R¹⁹ are independently hydrogen, deuterium, ahalogen, germanium group, a cyano group, a substituted or unsubstitutedsilyl group, a substituted or unsubstituted C1 to C10 alkyl group, asubstituted or unsubstituted C3 to C20 cycloalkyl group, a substitutedor unsubstituted C1 to C10 alkylsilyl group, a substituted orunsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2to C30 heterocyclic group, and n is an integer ranging from 1 to
 3. 2.The organic optoelectronic device of claim 1, wherein Z¹ to Z³ ofChemical Formula 1-3a-II, Chemical Formula 1-3a-III, Chemical Formula1-3a-IV, and Chemical Formula 1-3a-V are N.
 3. The organicoptoelectronic device of claim 1, wherein R¹ of Chemical Formula1-3a-II, Chemical Formula 1-3a-III, Chemical Formula 1-3a-IV, andChemical Formula 1-3a-V is selected from substituents of Group I:

wherein, in Group I, * is a linking point.
 4. The organic optoelectronicdevice of claim 1, wherein the second host is represented by one ofChemical Formula 2A, Chemical Formula 2B, Chemical Formula 2C, andChemical Formula 2D:

wherein, in Chemical Formula 2A to Chemical Formula 2D, Y¹ and Y² areindependently a substituted or unsubstituted phenyl group, a substitutedor unsubstituted biphenyl group, a substituted or unsubstitutedcarbazolyl group, a substituted or unsubstituted dibenzofuranyl group,or a substituted or unsubstituted dibenzothiophenyl group, L^(a1) toL^(a4), L³, and L⁴ are independently a single bond, or a substituted orunsubstituted C6 to C20 arylene group, and R^(b1) to R^(b4) and R⁵ to R⁸are independently hydrogen, deuterium, a cyano group, a substituted orunsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6to C20 aryl group, or a substituted or unsubstituted C2 to C30heterocyclic group.
 5. The organic optoelectronic device of claim 4,wherein R^(b1) to R^(b4) and R⁵ to R⁸ are independently hydrogen,deuterium, a cyano group, a substituted or unsubstituted phenyl group, asubstituted or unsubstituted biphenyl group, a substituted orunsubstituted pyridinyl group, a substituted or unsubstituted carbazolylgroup, a substituted or unsubstituted dibenzofuranyl group, or asubstituted or unsubstituted dibenzothiophenyl group.
 6. The organicoptoelectronic device of claim 1, wherein Chemical Formula 4 isrepresented by one of Chemical Formula 4-1 to Chemical Formula 4-6:

wherein, in Chemical Formula 4-1 to Chemical Formula 4-6, X² is O or S,R^(c1), R^(c2), R^(c3) and R¹⁴ to R¹⁹ are independently hydrogen,deuterium, a halogen, germanium group, a cyano group, a substituted orunsubstituted silyl group, a substituted or unsubstituted C1 to C10alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group,a substituted or unsubstituted C1 to C10 alkylsilyl group, a substitutedor unsubstituted C6 to C20 aryl group, or a substituted or unsubstitutedC2 to C30 heterocyclic group, and n is an integer ranging from 1 to 3.7. The organic optoelectronic device of claim 1, wherein: the secondhost is represented by Chemical Formula 2B:

wherein, in Chemical Formula 2B, L^(a1), L^(a4), L³, and L⁴ areindependently a single bond, or a substituted or unsubstituted C6 to C20arylene group, R^(b1), R^(b4), and R⁵ to R⁸ are independently hydrogen,deuterium, a cyano group, a substituted or unsubstituted C1 to C10 alkylgroup, or a substituted or unsubstituted C6 to C20 aryl group, and Y¹and Y² are independently a substituted or unsubstituted phenyl group, asubstituted or unsubstituted biphenyl group, a substituted orunsubstituted carbazolyl group, a substituted or unsubstituteddibenzofuranyl group, or a substituted or unsubstituteddibenzothiophenyl group.
 8. The organic optoelectronic device of claim7, wherein Chemical Formula 4 is represented by Chemical Formula 4-1:

wherein, in Chemical Formula 4-1, X² is O or S, R^(c1), R^(c2), R^(c3),and R¹⁴ to R¹⁹ are independently hydrogen, deuterium, a halogen, asubstituted or unsubstituted silyl group, a substituted or unsubstitutedC1 to C10 alkyl group, a substituted or unsubstituted C1 to C10alkylsilyl group, or a substituted or unsubstituted C6 to C20 arylgroup, n is an integer ranging from 1 to 3, “substituted” refers toreplacement of at least one hydrogen of a substituent or a compound bydeuterium, a halogen, a C1 to C4 alkyl group, or a C6 to C12 aryl group.9. A display device comprising the organic optoelectronic deviceaccording to claim 1.